Tubular oil heater



Nov. 3, 1931. A. CHRISTY TUBULAR OIL HEATER Filed Feb. 16.

1929 2 Sheets-Sha i j v 2 3 gwuemtoz All 6/2275? NOV. 3, 1931. c s1,830,505

TUBULAR OIL HEATER Filed Feb. 16, 1929 2 Sheets-Shae! 2 gwvemto oflza/mszy W 1% WW.

Patented Nov. 3, 1931 UNITED STATES PATENT OFFICE ANKER L. CHRISTY, OFCHICAGO, ILLINOIS, ASSIGNOR TO GYRO PROCESS DETROIT, MICHIGAN, ACORPORATION OF MICHIGAN comm, or

TUBULAR OIL HEATER Application filed February 16, 1929. Serial No.340,556.

This invention relates to improvements in oil heaters and has to doparticularly with heaters of the type employing tubes or pipes throughwhich the oil under treatment is passed and subjected to the influenceof elevated temperatures produced by passing heated gases through afurnace setting in which the tubes or pipes are stationarily p0-sitioned. The oil in passing through the pipes may be heatedsufliciently to vaporize or partially vaporize the same or may be stillfurther heated to effect molecular decomposition thereof.

In heaters of this type improved results have been secured by placingwithin the tubes longitudinally extending cores, which being of smallerdiameter than the internal diameter of the tubes or pipes, serve toprovide substantially annular passages between the adjoining walls ofthe cores and tubes through which the oil or oil vapor under heattreatment is passed. In this manner very efficient heat transfer betweenthe walls of the tubes and the oil undergoing treatment is permitted,since the heat is imparted to the oil by contact with the latter withthe heated surfaces of the tubes with which the oil comes into contact.If the cores were omitted there would be a tendency to overheat the oilwhich comes into contact with the tube surfaces and to detrimentallycrack or overheat the same and yet not to secure sufficient heating ofthe inner body of oil passing through the tubes, particularly when theoil is in the dispersed phase, since a vaporous or gaseous body is arelatively poor conductor of heat. To avoid this condition, it has beenproposed that such tubes shall be of small diameter but in practice thishas been found to be objectionable for various mechanical reasons, sincethe plan involves the employment of a great number of tubes anddifficulty is encountered in connecting serially the ends of the varioustubes and also to effect the support of the tubes in the furnace settingso as to overcome the tendency thereof to sag or drop under the highinternal temperatures of the furnace.

The present invention therefore provides a tubular heating element inwhich is removably positioned a plurality of longitudinally extendingcores so located that a relatively thin annular passage is providedbetween the adjoining Walls of the cores and heating element throughwhich the oil under treatment is passed, the tubular heatingelementpurposes between the oil vapor and the heated surface of thetubular element, allowing a tubular element of satisfactory strength anddurability to be utilized.

It is another object of the invention to arrange the cores within suchtubular elements in axially offset or eccentric relationship to the truelongitudinal aXisof said element. This is done in order that there willbe a greater space forrthe flow of the oil vapors along that side of thetube which receives the greatest heat input. Of course, if the tubereceives heat to an equal degree on all sides then the core is locatedin the true axis of the tube, but this is a rare condition in 'vide forefiicient contact for heat transfer furnace design, for the reason thatthe tubes ordinarily occupy what is known as a tube chamber throughwhich the furnace gases sweep or flow in a single direction. Therefore,in order to obtain the maximum benefit and heat transfer it has beenfound that by placing the cores to one side of the true axes of thetubes improved heat transfer is secured between the furnace gases andthe oil vapors under treatment in said tubes.

A further object resides in the provision of means for looking orpositively retaining theQSbg;

cores in fixed positions within the tubes, 'preventing loss of positionof the cores by rotation or from other causes.

With these and other objects in View which will appear as thedescription proceeds, the invention consists in the novel features ofconstruction;combinations of elements and arrangements of described anclaims.

parts hereinafter to be fully pointed out in the appended oil' converteror heater formed in accordance with the present invention, Figure 2 isan enlarged vertical sectional view taken through one of the tubes .of,the

heater and disclosing the same provided with the internal core formedin' accordance with the present invention,

'Figure3 is a vertical transverse sectional view taken on the line 3-3of Figure 2, i

T Figure 4 is'adetail perspective view of one of the cores. 1

Figure 5 is anenlarged vertical sectional view taken through the inletheader,- Figure 6, is a side elevation of one of the leg-members for thecore, i a

Figure '7 is-an enlarged vertical sectional view'taken through a tubehaving a core of a slightly modified form, a a

Figure 8 is an end elevation thereof, and Figure 9is an end elevation ofone ofthe cores. r

H Referring moreparticularly to the drawings, the numeral 1 designatesan oil heater 'or converter: formed in accordance-with the presentinvention. As usual, this heater comprises a setting 2 provided withaninternally; arranged bridge wall 3 which divides the' settininternally into burner and tube cham rs 4 and 5 respectively. Supportedv by the walls of the setting 2 and the bridge wall 3, and'arra'ngedwithin the tube cham-' ber 5, are rows or passes of longitudinallyarranged tubes 6 through which the oil under treatment is circulated.The entrance row of I the tubes 6 also passes through the burner chamber4 in order that the entrance portion of the first pass of tubes maybesubjected directly to the intense radiant heat developed within thechamber. This first pass or row of tubes is indicated by the numeral 6*,and

its entranceportions are connected with a header 7 into which an'oilline 8 is led from other suitable apparatus. In the particularheaterunder consideration the oil flows into the header 7 in a vaporousstate and-isthen distributed uniformly to each of the tubes Iconstituting the first pass 6. The entrance ends of the tubes in thepass 6 are provided with orifice'plugs 9. These plugs are formed withcarefully diametered axial passages, so disposed that an equal volume iof oil will flow into each of the tubes constituting the pass 6. a

The oil or oil vapor after flowing through the pass 6' enters a secondheader 10 ar-- rangedatthe rear end of the setting 2, and

from'thi's latter header the oil vapor passes into the next lower row orbank of tubes 6",

and after traversing this bank of tubes theoil vapor enters a thirdheader 11 arranged in the bridge wall 3, and then flows through thelower rows of tubes 6- and passes from these tubesto fractionating orother apparaing through said tubes, to temperaturesin excess of lOO0- F.I prefer to employ tubes wherein cracking reactions are permitted to tusnot shown. "In lieu of headers 10. and 11 individual return bends maybeprovided bebut may possess a diameter of app-roximately three inches andof materials which will stand furnace temperatures of from 1500 to 2000F., particularly when the tubes are wherein the oil vapors are heated,while passof such relatively large diameter for the rea used in theconstruction of an oil converter son that they withstand furnaceconditions to far better advantage than tubes of much smaller diameter[However, inorder toprovide for efiicient heat transfer, due to the usestituting one or more of the passes 6, 6 and 6 are provided internallywith longitudi-' nally aligned cores '12. In the present in-' stancethese cores have been shown as posi-.

tioned in the top rows 6 and 6", the row 6 .Qf these relatively largetubes, the tubes con- 1 serving as a soaking zone through which the oilvapor flows *at reduced velocity and take place to perhaps a greaterextent than in the previous passes. These cores produce substantiallyannular passages in the tubes inwhich they are situated for oil vaportravel. The vapor is most effectively heated by coming into contact withthe heated surfaces of the inner tube wall. A gas-to-metal therefore theannular passage, which is desfer. If the cores were omitted the oilvapor contact produces goodheat interchange, and

passing through the center of the tube would not be apt to attain thesame temperature. as that portion of the oil vapo'r contacting with thetube walls, and this condition has. re

sulted in the employment of unnecessarily high furnace temperatures. 7This results, first in an unequal circulation offheat, sec- 0nd, in theoverheating of that portion of the oilvapor which contacts directly withthe; tube walls, causingvexcessive decomposition of that oil vapor andthe production of excessive gas and, third, the underheatin of the bodyof oil which does not come into direct contact with'the heated surfacesof the tubes'.-

It is. knovvn that poor efficiency obtains in the matter of heattransfer between gaseous bodies as compared with heat-transfer between agaseous body and a solid body.

Therefore, by the inclusion ofv the cores 12 within certain or all ofthe tubes 6, I 'amenabled toemploy tubes of standard mechanical designand'strength andyetobtain a a resoroe to' say, with the longitudinalaxes of'said tubes offset with respect to corr espondingv axesof thetubes. This is' done'in order that passages 13 will possess theirgreatest area ,on that side of the tube which receives the greatest heatinput. In practice,.the tubes arearranged in the tube chamber and itwill be observed that the furnacegases travel downwardly through thischamber from'the I top or ceiling of the setting toward the bot- 4 tomthereof, where said gases find outlet from the setting through astac'kopening 14. Therefore,'in the chamber 5 the cores are p0- sitioned sothat the vapor passages 13 have their portion ofgre'atest area. disposedtoward. the tops of .said tubes and, conversely,v the portion of lessarea atthe bottoms of said tubes. The cores in the first passof tubes.6, which are disposed in registrationwith the burner chamber 4 arelocated in substantial- .ly the reverse order to that described above,for the reason that the'greatest heat input is from the bottom of thatportion of the'tube 6 which passes through. the chamber 4:. Each of thecores .12 consists of a suitable length oftubing which may be, forexample, 12 'inches'in length and if the internal di'-. ameter of thetubular heating element should be 25-64 inches the outside-diameter of}the core section maybe 2.25 inches. This ratio in diameters provides fora vapor passage "13 of desired area. The core sections may be formedfrom the same materials as the tubular heating elements. To support thecores within the tubular heating elements, each of said core sections isprovided, contiguous to its opposite ends, with annular grooves 15,

which receive split metallic rings 16. These rings conform substantiallyto the outside diameter of the core sections, said rings, however, areprovided-with outwardly struck legs 17. which engage with the innerwalls of the tubular heating elements 'to properly support the coresections" in their applied positions.

When the cores arearranged eccentrically within the tube sections it isdesirableto pro vide means for positively retaining the'cores. in sucheccentric positions to control efi'e'c tively the shape of the vaporpassages 13.

This end is primarily obtainedby locking the core sections againstrotation; A convenient method for accomplishing this consists inproviding the end core sections with radiall movable prongs or pins 18which are slidably mounted. in'radial openings l9formed in the cores.Each of these pins includes a beveled inner end as at 20, and engageablewith the beveled end'of each pinis a set screw 21 hav- .ing 'a'conicalend. .Thissetscrew is acces siblefrom the endof the tube, and it will beseen that byrotati'ng the samein afclock wise direction, the pin 18' maybe forced outwardly and. radially to bite into the inner wall of thetube- This engagement is so positive as q to prevent rotation of thecores or lossof position thereof. The set screw construction described,however,is only provided in con- 'nection with the core sections locatedat theends of the tubes, and the remalning sections aligned c oresection, there being an opening 23 formed in the wall of said aligningcore.

section to receivethe protruding end of .the

ffinger 22. This connection is carriedout inthe remalnlng core sectionssituated 1n the tubes.

Inthe modified form of construction dis- 'closedin Figures 7,8 and f thedrawings, the core members 24 have Welded. thereto at it'sends shortpin-sections 25 which serve as legs for the corejwhen the latter ispositioned withinthe tubular/heatingeleinents. As the sity of pointingthe radially movable for holding the cores in place.

In view of. the foregoing it will be seen that the present inventionprovides an im-' proved oil heater of the tubular type or socalled pipestill variety wherein eficient heat passing through the tubes and theinternal heat developed within .the setting of the heater. Thisissecured mainly by the'provision of the removable cores which'providessi'multaneously for the employment of large diameter tubes and yetprovides for efi'ective heat'transfer. The'core sections'may be re- 7moved from the tubes to admit of their clean-v .pins or legs 25 arepositioned longitudinally, of the core 24: it will be seen that theyoffer a broad bearing surface to the inside of the tubes and thuseliminate the useof and neces-i pins 18' transfer. takes place betweenthe oilvapor ing from time to time and, furthermore, are 4 constructedfor the purpose of-obtaining cient form and location.

, Vihat is claimed is: v

1. llnan .oil heater, a

be passed, a plurality of longitudinally alignedcore sections arrangedin. said heat ing eleinent,-meansfor supporting said core sections inspaced relation from the inner .wall of the tubular heating element todefine a substantially annular vapor passage, and y means forretaining'the core sections in fixed positions in connection-with thetubular heating element.

ment, a plurality of core sections arranged 2. In an oil heater, atubularheating elei the inner walls of the latter toprovide a substantially" annular vapor passageway, spacing elements carried by eachof said core sections' and arranged to engage with the inner' walls ofthe tubular heating element, and

- means co operative with said core sections for Y restraining thelatter againstaxial rotation" within the heating-element.

3. In an o'l heater, a'tubular heating ele-- ment, a plurality ofseparable core: sections arranged longitudinally within said heatingelement, the outer walls of said core sections bein spaced from theinner walls of the heatmg 'eleme'nt, said core sections having the endsthereof provided with circular. grooves, and supporting rings positionedwithin said grooves and provided with radiating 'legportions, the latterbeing adapted to engage with the inner walls of the tubular heatingelement to effect the support of the .core sections therein.

4:- In an oil heater, 2:: tubularhcating ele ment, a core sectionpositioned within said heatmg element, said core section consistingof acylindrical metallic body of substantially uniform diameter throughoutthe length thereof, means'carried by said core section for supportingthe'latter-within saidv ment, an eccentrically mounted pin projectingfrom one end of each of said core sections and arranged. to be receivedwithin openings formed in the complemental ends of registering sections,said pins serving to prevent relative axial rotation between saidsections.

, 8. In an oil heater, a heating tube,la core" positioned in saidtubeand. extending longitudinally thereof, the outer walls of the corebeing spaced fromthe' inner walls of-said t'ubeto provide alongitudinally extending annular passageway for high ve ocitytravel mgsaid core in spaced operative relationship with respect to the innerwalls of the tube and providing for free unobstructednonturbulent. flowof the oil vapor through said of oil vapor, supporting meansfor'maintaim passageway, and means for positively re-- tainingsaid Icorewithin said tube and secure against axial and longitudinal displacementwith respect thereto.

In testimony whereof I aflix my signature.-

ANKER Ii. CHRISTYI.

heating element in axial oflset' relationship 1 to the longitudinal axisof said heating ele-' ment, and'fric tional means forp'ositively lockingsai 'tation within the heating element.

core section against axial roi 4 the heatin element and with thelongitudinal axis 0? each core section ofiset with respect'to thecorrespondin axis of the heatingelement, and means or positivelylocking/ said core sections'in fixed positions within saidheating'element.

6. A core section forjtubular' oil'heaters coin rising a cylindricalmetallic body of substantially uniform diameter throughout .the lengththereof, said section being pro;

vided with circular grooves at its opposite ends, resilient ringsarranged to'be posi-j tioned 'within said grooves, said rings beingprovided with integral radially extending legs for effecting the supportof said core s'ection, and a radially movable pin carried by one end ofsaidcore section. "7. In an oil heater, a tubular heating element, aplurality of longitudinally aligned core sections arranged within saidheating element and disposed to one side of the heat- 3 'ingelement,means for supporting said core sections so that their walls arespaced from the inner walls of the tubular heating ele-

